Wet processing of tobacco stems

ABSTRACT

In this invention tobacco stems and/or fragments of stems, and/or portions of tobacco leaves containing stems and veins are water soaked or wet softened by water and or steam to completely soak the stems and veins and dissolve part of their soluble organic and inorganic constituents. The wet softened stems and veins are then fed to a refiner where they are mechanically opened by crushing or rolling. Thereafter, the opened stems and/or veins are fed to a drier where the moisture content is reduced to the level of the cut tobacco with which they are to be mixed.

United States Patent Quarenghi Sept. 12, 1972 WET PROCESSING OF TOBACCOSTEMS [72] inventor: Rodolfo Quarenghi, Bologna, Italy [73] Assignee:American Machine 8: Foundry Com- [22-] Filed: April 20, 1970 [211 Appl.No.: 29,850

[52}. US. Cl. ..l3l/140 R, 131/147 R [51] Int. Cl. ...A24b 03/04, A24b05/ 10, A24b 09/00 [58] Field of Search ..l3l/140 R, 147 R, 140P [56]References Cited UNITED STATES PATENTS 5/1952 Sowa ..131/140P 11/1965Molins ..13l/140R 9/1965 Jones ..131/140 R 10/1904 Lauhoff ..131/140RX3,513,857 5/1970 Silberman ..l3 l/l47 UX Primary ExaminerSamuel KorenAssistant ExaminerJohn F. Pitrelli Attorney-George W. Price and EliWeiss ABSTRACT In this invention tobacco stems and/or fragments ofstems, and/or portions of tobacco leaves containing stems and veins arewater soaked or wet softened by water and or steam to completely soakthe stems and veins and dissolve part of their soluble organic andinorganic constituents. The wet softened stems and veins are then fed toa refiner where they are mechanically opened by crushing or rolling.Thereafter, the opened stems and/or veins are fed to a drier where themoisture content is reduced to the level of the cut tobacco with whichthey are to be mixed.

2 Claims, 2 Drawing Figures PATENTEBSEP 12 I972 3.690.328

INVENTOR. RODUL F0 QUARE/VGH/ ATTORNEY WET PROCESSING OF TOBACCO STEMSThis invention relates to the treatment of tobacco and more particularlyto the method of and apparatus for treating stems and veins which are anintegral part of tobacco leaves, and parts of tobacco leaves such thatthe stems are converted into a form in which they can be readilyincorporated in smoking articles.

Heretofore, in preparing tobacco for processing into smoking articles,such as cigarettes and cigars, it has been necessary to remove stemseither by the use of stemming machines which strip the stems from thetobacco leaves, or by the use of threshing machines which break up theleaves and thresh the stem portions and large veins from leaves orlaminae, after which, by a winnowing section, the heavier stems andlarge vein pieces are separated from the lighter leaf or laminae partsof the leaves.

Attempts have been made in the past to utilize stems in smokingarticles, such as cigars and cigarettes.

. Methods and apparatus have been proposed for preparing them foraddition to stemmed leaves and threshed leaf. A common technique is tocrush the stems by steaming and rolling. However, the hard, splintycharacteristics of the stems remain and are carried over into the finalsmoking articles where they have the unsatisfactory effect of burning ata different rate. Also, small hard pieces of stems fall out of the endof cigarettes, the tongue and fingers detect the presence of stems dueto sharp points which sometimes puncture the paper wrapper. There is adeterioration in the taste of cigarettes, and the presence of hard spotsmakes it difficult for the final smoking article to assume proper shapeand form.

The present invention constitutes an important solution of the problemof utilizing stems and eliminating an obvious waste on the part of amanufacturer of smoking articles because it makes possible the use ofstems, which in the past, except for limited quantities, have been soldas waste for manufacture into tobacco by-products, fertilizer, and otherproducts which use stems.

According to the present invention, tobacco stems and/or portions oftobacco leaves containing stems and veins are water soaked or wetsoftened by water and/or stem to completely soak the stems and veins anddissolve part of their soluble organic and inorganic constituents. Thewet softened stems and veins are then fed to a refiner wherey they aremechanically opened by crushing or rolling. Thereafter, the opened stemsand/or veins are fed to a drier where the moisture content is reduced tothe level of the cut tobacco with which they will be mixed.

It is an object of this invention to provide a method and apparatus fortreating stems and/or veins to permit them to be mixed with cut tobacco.

It is another object of this invention to eliminate the woody rigidityof stems and/or veins without requiring the use of harmful substances.

It is still another object of this invention to provide treated stemsand/or veins which can be added to cut tobacco without altering thearoma and taste of tobac- It is also another object of this invention toreduce the unutilized portion of the tobacco leaf used in makingcigarettes and cigars.

It is yet another object of this invention to provide a method which issimple and a device which is economical to build and reliable inoperation.

The novel features that are considered characteristic of this inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its organization and method of operation, aswell as additional objects and advantages thereof, will best beunderstood from the following description when read in connection withthe accompanying drawings wherein:

FIGS. 1 and 2 illustrate, in sequence, the various steps of the processof the invention and the effecting of the steps in structure inaccordance with the principles of the invention.

The stems to be processed are fed to a belt conveyor 2, are thentransferred to an ascending metering belt 3, and are then fed to ahopper 4. The stems are, subsequently, introduced into a digester 5through a deflectable bottom discharge unit of hopper 4. The dischargeunit 6 of the hopper 4 is controllable to discharge either alternatelyor at will, into a digester 5 or into an emergency bin or bucket 7.

Digester 5 is equipped with a motorized agitator 105, an upper aperture205 through which water can be supplied and a bottom duct 305 forfeeding steam to the digester.

The stems within digester 5 are first subjected to a room temperaturewater soak. The processing period in the .digester may vary, forinstance, from 30 to 60 minutes. Its purpose is to completely soak thestems and dissolve part of their soluble organic and inorganicconstituents. In the water processing stage, the consistency of the stemdispersion in water may change from 5 to 10 percent.

Thereafter, in the digester 5, the water soak is followed by a steamprocess. Steam is fed into digester 5 through the bottom aperture 305,to gradually raise the temperature within the digester to C. in a periodof 40-60 minutes. Thereafter, this temperature is kept constant withoutany further steam feed but with the introduction of hot water and/orsteam into an outer jacket of the vessel.

At the completion of this process, the woody rigidity of the stem isreduced considerably. The stems are then fed to and opened by a conetype refiner 8 or a fluted roller flattener rotating at differentialspeeds, with the fastest roller rotating at a maximum of 300 RPM. Theadjustment of the working surfaces is effected by setting the workingclearance variable between 1.5 and 2.8 mm approximately.

The product obtained is fed to and carried by a perforated belt conveyor9 or other suitable means associated with an opened drained watercollecting case 10. The opened and drained stems are fed from the beltconveyor 9 to an elevator belt 11 which transports the product to adryer 12.

The drained water contains a considerable percentage of nicotine whichcan be used as a by-product. Moisture content of the product at thedryer inlet is 80 percent. At the outlet, the moisture content of theproduct is 30 percent and the product has features which are similar tocut tobacco. Thus, the product can be mixed with the cut tobacco priorto toasting the cut tobacco.

The product obtained with the process according to the invention is of afiliform nature, very similar to the cut tobacco and ensuring a goodcigarette filling coefficient. Furthermore, the process according to theinvention is not limited to the utilization of the stems selected in thecigarette makers, but is perfectly suitable for handling the stemsoriginating from other sources such as, for instance, from the threshingline without any previous flattening and cutting operation. Theeconomical advantages resulting from the elimination of the stemflattening and cutting lines are quite evident.

It is understood that the process according to the invention is notlimited to the embodiment which has been illustrated and described butthat many changes could be incorporated. Thus, for instance, with sometypes of stems, the process can be simplified by eliminating the use ofsteam. The room temperature water soak is in some instances sufficientto weaken the woody rigidity of the stems so that they can then passdirectly to the successive opening stage in the refiner. Furthermore,the above mentioned ranges of variation of the time and temperaturevalues can be widely changed in relation to the stem percentage quantityand the relative sizes.

What is claimed is:

l. A method of processing stems separated from cut tobacco to modifytheir woody rigid structure, comprising the steps of:

raising the moisture content of the stems to at least percent by soakingsaid stems in room temperature water for between 30 and 60 minutes, andthen steam soaking said stems,

opening the stems mechanically,

draining the opened stems to a moisture content of 80 percent, and

drying the drained stems to the moisture content of cut tobacco.

2. The method of claim 1, wherein the step of steam soaking said stemsraises the temperature of the stems to between C and C in less than 60minutes after the completion of said room temperature water soak by saidsteam soak.

1. A method of processing stems separated from cut tobacco to modifytheir woody rigid structure, comprising the steps of: raising themoisture content of the stems to at least 80 percent by soaking saidstems in room temperature water for between 30 and 60 minutes, and thensteam soaking said stems, opening the stems mechanically, draining theopened stems to a moisture content of 80 percent, and drying the drainedstems to the moisture content of cut tobacco.
 2. The method of claim 1,wherein the step of steam soaking said stems raises the temperature ofthe stems to between 125* C and 130* C in less than 60 minutes after thecompletion of said room temperature water soak by said steam soak.